Hydraulic elevator.



` Patented Nov. I3, |900. R. T. CRANE. HYDRAULIC ELEVATOR.

(Application led Dec. 26, 1896.!

3 Sheets-Sheet I.

Tm: uownls PETERS co.. Pnoro'urno.. wAsNmGroN, n c.

No. 66I,575.

(up Model.)

No. 661,575. Patented Nov. I3. |900.

l n. T.v CRANE.

HYDRAULIC ELEVATB.

(Application filed Dec. 26, 1896.)

(No Model.) I@

3 Sheets-Sheet 2.

No. 66|,575. Patented Nov. I3, |900.

R. T. CRANE.

HYDRAULIC ELEVATOB.

(Application filed Dec. 26, 1898.)

(Nn Model.) 3 Sheets-Sheet 3.

WMW

RICHARD T. CRANE, OF CHICAGO,

PATENT OFFICE..

ILLINOIS, ASSIGNOR TO THE OTIS ELEVATOR COMPANY, OF NEW JERSEY.

HYDRAULIC ELEVATOR.

SPECIFICATION forming part of Letters Patel-1t No. 661,57 5, dated November 13, 1900.

Application filed December 26, 1896y .Serial No. 617,036, \\lo model.)

.To all whom t may concern.-

Be it known that I, RICHARD T. CRANE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Hydraulic Elevators, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates to certain new and useful improvements in hydraulic elevators of the vertical type, and more particularly to hydrogravity-elevators in which the car or cage is lifted by the gravity of a falling weight and lowered by hydraulic pressure directed against, so as to lift, the weight.

The object of the invention is to provide a construction wherein are secured all the advantages and economical results as to cost of installation, maintenance, operation, and space occupied incident to the use of an elevalor of the type above referred to and at the same time to dispense with a piston, a piston fit in the cylinder, and an independent counterweight for the lifting-cables, and to provide certain novel details in the construc- 'tion and arrangement of the parts,all as illustrated in the accompanying drawings, in which- Figure l represents a diagrammatic elevation of an elevator apparatus embodying my invention, showing the cylinder for the ram or plunger in section. Fig. 2 represents a detail section through the check-valve casing. Fig. 3 represents a modied form of operating mechanism. Eig. 4 represents another modified formof operating mechanism. Fig. 5 is a detail longitudinal section through the lower end of the ram and cylinder. Fig. 6 represents a horizontal section on the line 6 (i of Eig. 5, and Fig. 7 a detail longitudinal section through a modified form of ram in the cylinder.

Similar letters of reference denote corresponding parts in all the figures of the drawings.

In elevators of the class to which my invention belongs to perform the service for buildings of considerable or even ordinary height a heavyweight is necessary, and as the space in which it maybe used is invariably valuable and restricted it is of course desirable that the weightshall be of such character as to occupy but little space and yet be sufficient for the desired purposes.

I have. found by practical demonstration in lthe use of a number of elevators embodying my invention that the best. results are attained by the use of a ram or plunger of substantially half the length of the lift or of the height of the building with buta single multiplying-sheave, this arrangement being most economical and advantageous from every point of View, as all of the apparatus is contained within the elevator-shaft, occupies the minimum space, requires the oilingand maintenance of but two sheaves, and involves the use of but one set of cables, and that only the length of the height of the building.

ln carrying out my invention I employ a guide-frame A of any desirable or suitable construction, which should be of a length equal to about one-half of the height of the building and located in the upper part of the building,and a plungeror ram B,which should be of a length equal to about one-half of the height of the building and arranged to work in a cylinder C, which should be of a length equal to about one-half of the height of the building and located in the lower part of the building. This cylinder may be of any desired and suitable construction and maybe supported in position in amanner that will be obvious to one skilled in the art, according to the requirements of the particular building in which the apparatus is located. I prefer, however, to have the cylinder C made up of a number of sections, as illustrated in the drawings, such sections being bolted or otherwise fastened together end for end and provided with bearings near the ends thereof, which serve only as guides for the rain or plunger, so as to avoid the necessity for a long bearing of the ram or plunger throughout its length and the excessive friction resulting therefrom. It -will be borne in mind, however, that the ram should not have a piston fit in the cylinder, but, on the contrary, a sufficiently loose fit to permit the free passage of water between the ram and cylinder, which condition is greatly promoted by having IOO the series of guide-bearings in the cylinder, with the remainder of the Wallsof'the cylinder well separated from the ram instead-of simply a loose ram in a plain cylinder.

The purpose of the loose or free fit of the ram in the cylinder is to enable the cylinder to be keptfnllof water at all times,- whether the ram is wholly or partly withinthe same,

the maintenance of a hydrostatic column of Water in the cylinder being of the.utmostim. portance, as will appear farther on'. Obvi# ously various other means may be adopt-ed for providing thisV hydrostatic colu mn in the cylinder-such, for instance, by grooviug Aconvenient manner.

the cylinder or by having the ram'-t'loosely in a uniformly-bored cylinder and provided with a cross-head or guide ofY any suit-able character.; bntall such modifications `or a'ny otherconstruction that enables the-maintenance atall times of the hydrostatic columnr in the cylinder are within the purview of maya invention.

It is necessary, of course, in orderto maintain the hydrostatic column that the upper end of' the cylinder through which the ram` Works" should be closed, and to accomplish this 1V prefer to use a simple stuffing-,box D,-, closing the end of the cylinder and throughwhich the ram works, which boX mayv be.

readily removed and repacked when necessary Without removing the ram) or-disturbing.

anyother parts of the apparatus..

Theupper `endofY the ram or plungerpro-y jects vbeyond the cylinder when the ram is in its lowest positionvin the cylinder, anditfcarries at its upper end across-headE, which engages the guide-frame A. and serves-toy guide and steady the upper end of the plungeriafter it leaves the cylinder,` the detailed construction of the cross-headbeing obvi ously immaterial to my present invention.x Supported upon the cross-headis'aframe F, in which is loosely journaledfa multiplyingsheave G, around which are trained the ilfting-cables H, one end of whichlatter is an. chored atl to the upper end of. the guideframe A or any other suitably-tixedpart, the

otherends of the cablesbeinganchored to the frame of the car J in any well-known and= The liftingfcables, as`

usual in elevator constructions, are trained overthe idler-pulley or main sheave K at-the4 'top of the elevator-shaft.

At the top of the guide-frame A may be located a spring-buffer L, against which the frame F im pactsjust before the frame reaches the limit of its upper travel, and consequently just before the car or cage reaches the limit of its lower travel, while at the lower end of the guide-frame may be arrangedavpair of spring-buiers M, against which the crosshead impacts just before reaching the limit` of its downward travel, andi consequentlyjust-.before the car or cage reaches the limit of its upper travel. These buffers serve as spring-stops for the elevator at both limits of its travel and prevent violent or dangerous shocks to the car and its operating and accessory mechanism in stopping at either-limit of its movement.

For the application of hydraulic pressure `to the cylinder to lift the ram or plunger l prefer to have the water-inlets located above the ylower-end of the cylinder, preferably at N andO,v respectively, one being below and the other above the lowest bearing P for the ram orplunger in the cylinder. Any suitable apparatus may be employed for forcing the Water into the cylinder and for cont-rolling the supply to and discharge thereof from the cylinder, the particular construction and arrangement-of such apparatus forming no part 4ofthe present invention.

The supply ofwaterth-rough the water inlets or-"ports N and-Oissmultaneous, while the liflingeect of the water admitted at the upper portis somewhatthrottled by the interposition of the lowermost bearing in the cylinder until theendof the ram passes the same, after which time the water admitted at. both ports operates with full and unrestricted force. fhowever, of providingthis succession of ports through which the water is admitted to and discharged fromthe cy-li nderoccu rs in thedis- 1chargeof the watery from the cylinder, when ,the waterV may; be utilizedasan automatic stop,V for theram or plunger.

Thev principall advantage,

So far as relates tothe 'broad idea fof myinvention it-is immaterial whether one or more inlet and-discharge lopeningsbe employed'or 4whether the water is admitted and discharged through the same. inlet orin'lets. Theloca- Ation ofthe supply anddischarge ports above thelower endlof the cylinderprevents the completedischarge-of the water from the cylinder, and the Water thus retainedin the cylyinder may be utilized as a gradual stop for the plungerby tapering the lower' end ofthe lplunger below the upper supply-port() o r by providingtaperi ng grooves on the sides of the plungers, so that as the plunger passes beyond the lowermost bearing P in the cylinder the escape ofthe Water in thelower end ofthecylinder throughl the port O willv be gradually throttled; the resistance of the waterto the downward movement-of the plunger materially-resistingthe travelofthe plunger vicesfor accomplishingIv this result are il1us tratedin Figs. 3 ande and will be described farther on.

As between a weighted `piston for liftingthe izo car, which I am aware 'is old, and a ram or plunger such as I have herein described, working freely in the cylinder, by which I mean in such manner as to permit of the maintenance of a hydrostatic column in the cylinder through which the ram falls, there is a wide difference mechanically as well as in the results produced. In the first place a weighted piston must have a piston iit in the cylinder to be operative, and such a piston fit in a cylinder of the length required in practice it is practically impossible to maintain, and if possible to maintain would involve great waste of power to overcome friction and binding as compared with my freelyworking ram. Furthermore, the packing of the piston must be frequently renewed, and this can only be done bycompletely withdrawing the piston from the cylinder, an operation involving great waste of time, both in the packing and in the enforced idleness o1n the elevator. The packing for my ram is in a stufiing-box at the upper end of the cylinder, through which the ram Works with the minimum friction, as reliance need not be placed upon the stuffing-box as a guide for the ram, and the renewal of the packing is a very simple manner and can be accomplished without the removal of the ram from the cylinder, as is perfectly obvious.

In practical operation a weighted piston, if operative at all, in a cylinder of practical length, would soon cut the cylinder so as to necessitate the removal of the cylinder from the building for-reboring or the substitution of a new cylinder, besides involving the enforced idleness of the elevator in the Incantime. In the use of my ram all danger of cutting the cylinder is avoided, because no piston is employed. In addition to all of these practical advantages of the ram over the weighted piston there are the further important advantages incident to its use in the provision of means for maintaining a hydrostatic column through which the ram falls, thereby enabling the utilization of the changing displacement of the ram to counterbalance the changing weight of the lifting-cables. This cannot be done with a Weighted piston; but, on the contrary, an independent counterbalance, such as the well-known counterbalance-chain suspended from thel car, must be employed as a counter-balance for the changing or shifting weight of the lifting-cables.

Another important advantage is the capability of use of the ram in connection with a succession of supply and discharge ports along the cylinder as an automatic stop for the rain at the limit of its downward travel, whereby are avoided' dangerous shocks and jars, which would otherwise occur. By having the ram work freely in the cylinder instead of with a piston tit, like a piston, the cylinder is maintained full of water, so as to provide a hydrostatic column therein at all times and under all conditions, which may be taken advantage of to provide an automatic counterbalance for the running cables, and thus dispense with the usual counterbalancechain attached to the car or other independent counterbalance, with its necessarily-accompanying cables. Another important and desirable result attained by maintaining a hydrostatic column in the cylinder at all ti mes is that it prevents the possibility of air getting into the cylinder, with the accompanying evils resulting therefrom. It is immaterial to the broad idea of my invention how or by what means the hydrostatic column is maintained under all conditions; but for the purpose of illustration I have shown in the drawings three arrangements by which this most desirable result may be accomplished.

In Fig. l I have shown the application of a tank a, located on the roof or in the upper part of a building, which tank or some other suitable source of constant hydraulic pressure is connected by a pipe b with the cylinder C, preferably near the upper end thereof, and has a check-valve c located therein, which valve may be of any suitable construction so long as it is arranged to open toward the cylinder, but will close so as to prevent the outflow of water from the cylinder. In this construction the hydraulic lifting-column directed against ihe end of the ram is obtained from any suitable source and admitted through the openings N and O, or eiher of them, near thelower end of the cylinder, and by reason ofthe loose iit of the ram in the cylinder or the passages provided for the free run of the water past the ram the water thus forced into the cylinder at the bottom will fill the cylinder to the top, and suiicient pressure should at all times be maintained to keep the cylinder full of water, such pressure obviously being not sufficient to lift the ram. In any event should the pressure fall sufciently to temporarily lower the head of the column of water in the cylinder the loss will be instantly supplied by water from the tank a, which is free to dow into the cylinder, but cannot flow back therefrom to the tank. In the same way should the pressure in the cylinder be instantly cut od while the ram is rising, or should the latter, by reason of inertia, continue to rise, thereby tending to produce a vacuum at the end of the rain, such vacu um will be instantly dispelled by the supply of water which will be thereby drawn into the cylinder from the tank a. This action serves to prevent the falling back of the ram after the force of inertia is overcome, which would result in serious and damaging shocks to the elevatorcar and the accessory parts. This action also serves to prevent the drawing in of air which would follow but for the free inlet of water to the cylinder from the tan-k, so that under any conditions the possibility of air getting into the cylinder is avoided. Should it forany reason be undesirable to maintain sufficient pressure from the source of hydrau-f lic supply to keep the cylinder at all times full ICO IIO

oflwater, this service can be performed Iby Ithe tankcnwhich, asbeforestated, may-be located.- at any suitable point and can besupplied with" waterfrom any source'.

InFig; 3 I have shown another mechanisml for keeping the cylinder full of? water'v atE-all times', which, though@ contemplated by-` the broad idea ot.l my invention", is not-'specifically off myinvention, .but-is herein fillustrated fas beingone of theforms in which myinven-V tion has been practically embodied-inlelevator apparatus-.nowin daily service; apparatus VI provide a stand-pipe' d, through which the water fromy the cylinder isdischarged, a suitable arrangementofcontrolvalves beingusedA in connection therewith, (which itfis-nottnecessaryfto illustrate or describe' iti-'detail h`erein,) whereby' the lWater may hela'dlnittedtothe openings-N and'O;V or either: ofthem, w'hile the stand-pipe yisfcut ofi` froxnzcomrnunication with thefcylinder, but' which =wi'll establish 1 communication besV tweenrthe stand-pi pe vand the cylinder when ever the discharge offthe water isd'esira-ble.

Obviouslyy the'head of the column ini the` cylinder can :neverfall below-the head ot the columnin the standpipe, and as the latterr is extended upstoa pointsubstantiallyeven with the top of the cylinder the cylin-derw-i'll be at'alltimeskept full.

In Fig.m4'I have shown still another apparatus for keeping the cylinder :`ullfof"water1,I in-which the pressure-tank le is substituted for the stand-pipe, the pressure-tank normally containingsufcient air or other pres-l sure to sustain thev column of iwater the'heightl ofthe ,cylinderp 'Ihis tank may form aportion offthe usual circulatingfpumping system' from which-tl1epump-supply is drawm.

Inail forms of my invention the chang-` ing dis'place-ment'of the ram orlplunger may' loe-utilized to counterbalance the changing weight'of the lifting-cab'lesin their run to'op'- posite sides. of' the main sheaves. Ivm-ay here state, however, thatthe invention involving' the utilization of the changing displacement of the ram-to-counterbalance thechangingweight-of the liftingf'cables by proper proportionlof the displacement caused byl'h'e'ram" to the weightof the lifting-cables is not myinvention, but is that of George H. Reynolds, whose application -for patent for saidinvenltion was led1 March 27, 1895, Serial; No.: 543,381, and I therefore do not'desire to hereinclaim the invention by which that useful and desirable result'is attained; It is wellunderstood that the ram when immersed in the hydrostatic column theoretically loses a certain portion of its weight perffoot, depending upon the displacement caused thereby, and

that, conversely, as the ram emerges from the hydrostatic column it theoretically acquires Weight, or, in other words, regains the weight lostlby immersion. This principle holds good whether the ram is solid or hollow (if closed) throughout its length or partially solid'and partially hollow, asillustrated in Fig. 7, andV In this" vmainr shea-ve. practically yremains the f same throughout its inder through said pipe.

also regardless'ot 'the shape-or configuration of the ram, and so long asl the ram has'sufficient weight'l to lift thelcar `and its-accessory parts itsl shape or-constructionwould fall within my invention; button-take advantage of this displacement#'forthepurp'oses of a counterbalanfce'for 'the changingnveight ofi the liftingcablesa certain proportion mustcxist'between vthe displacement causedhythe ram and the tioned thatth'e weight ofthewate'r displaced `by' itper-foo'tiwilt equal the weight of two feetfotthe lifting-cables, itv willbe readily seenthat-asthe ram falls each foot it will lose` in weight the amount gainedrby the .weighltof the'two feet of the lifting-cables vrunning to its side of the 'main sheave, and,

onthe other hand; wheny the r'am'is rising it 'gains in weightf'eachf foot-an amount equal to the lossrof'w'eight froml thev running'of two feetof 'the lifting-cables to the carside ofthe Hen-ce the Weight of the ram movements up and down, andthe same power will'move it in allpositions; t

rEhe detail mechanism illustrated infFigs.

and t doesrnot -forma specivc part of my invention; but Imay state generally that in both f1 isa supply-pipefrom the pump or otherf sourcel of pressure, g is the changevva'lveh is ea'pipe lleading from the changevalve:totheopenin-gOin the cylinder, z' is another; pipe leading fromfthe change-valve Ato Ithe `opening Nin the cylinder, j is the discharge-pipe, leading to the stand-pipe d or the pressure-tanke, and la and lare branches "ofthe pipe-Q1, inthe former'of which is located a throttling-valve m and in the latter of which valve m'isadjustable, so' as to render the passage of-water through the pipe 7c in either direction more or lessl restricted, as desired. The check-valve 'n opens upon movement of the water toward the pipe t' and lclosesa gainst a return movement of the water.

The pipe lhlisseveral times the' capacity of the pipe 7l, thereby permitting a comparatively free flow` of water to and from the cyl- Thisrelation of size, however, isnot essential, and-the pipes may be ofthe same capacity or reverse, the principal point beingto have the two passages for the escape of waterfromthe lower end of the cylinder through the pipe 'L' to the IIO discharge-pi pe in order to utilize the retardation of the water as a stop for the ram. It will thus be seen that the pipe h is practically cut off by the ram when the pipe i comes most actively into play, although both pipes operate simultaneously in forcing Water into the cylinder. As the water is being discharged from the cylinder the comparatively free discharge afforded by the pipe Zbranching from the pipe t' will be closed by the check-valve n and the water will be compelled to pass through the restricted passage m.

Of course it will be understood that the elevator-car, with its accessory parts, must be of a weight more than sufficient to counterbalance the lifting-cables between the main sheave and the ram when the ram is in its lowest position, so that the car will start promptly when the ram is lifted, thus allowing the car ro fall.

An elevator apparatus constructed in accordance with my invention is simple, durable, and economical in lthe maximum degree, and is of such construction that it will not easily get out of working order and may be easily and quickly repaired if it does, besides which my invention possesses the maximum ad vantage in the cost of installation, maintenance, operation, and space occupied.

Having thus fully described my invention, what l claim, and desire to secure by Letters Patent, is-

l. In an elevator, the combination of a car, a ram, cable connections therebetween, a closed cylinder in which said ram works, and having an internal diameter greater than the `tain said cylinder constantly filled with Water, means for controlling the supply of said water, whereby the ram is raised by said pressure to lower the car, and means for con# trolling the exhaust of said Water from the cylinder, whereby The car is raised and the weight of the hoistingfchain is compensated by the fall of the ram in the cylinder, as and for the purpose set forth.

2. In an elevator, the combination of acar, a ram, cable connections therebetween, a closed cylinder in which said ram Works, having an internal diameter greater than the diameter of the ram, a series of guide-bearings for said ram at intervals in the cylinder through which the ram freely works, said ram being externally tapered to permit of the passage of the operating medium about said ram, supply and exhaust openings for said cylinder adjacent to the lower end thereof but somewhat removed therefrom, and means for controlling the supply of water to and exhaust thereof from said cylinder, whereby said cylinder is constantly maintained filled and the ram is raised and lowered, as and for the purpose set forth.

RICHARD T. CRANE.

Witnesses:

W. R. OMOHUNDRO, C. L. Woon. 

